Well I have SvR 2006,2007,2008,2009 and they run on my emulator pretty well,but when I got SvR 2010,it gets a lot slower.2010 looks to me a lot like 2009 but with better graphics.I'm using GSdx SSSE3 0.1.15 with PCSX2 1888.My PC specs are:
2GHz
1.7 RAM
Intel Pentium Dual Core CPU
Windows XP.

As you said, the game is prettier. That usually means it also demands more of your hardware, hence the slower performance.